1. Field
The present general inventive concept relates to a fabricating method of a semiconductor device.
2. Description of the Related Art
An increase in integration of semiconductor memory device has been in demand to meet the market requirements for higher performance and reduced cost. In particular, increased integration is required because the degree of integration of semiconductor memory devices can be an important factor in determining the product price. In the case of the conventional 2-dimensional or plane semiconductor memory devices, the degree of integration is mainly determined by the area occupied by unit memory cell. As a result, fine pattern formation technology plays a great role in the degree of integration.
However, since high cost equipment is required for forming fine patterns, the degree of integration of 2-dimensional semiconductor memory device has been limited although it has been increasing. To overcome this limitation, vertical cell string structure that forms memory cells in 3 dimensions has been researched. With vertical cell string structure, the end part of the semiconductor device must be formed to have a step shape so as to form contact parts configured to connect the vertical cell string and the signal interconnect.